Supply apparatus for peening components



United States Patent Us. or. 137561 2 Claims ABSTRACT OF THE DISCLOSUREThis invention is directed to a supply system for supplying peeningmaterial, such as a slurry, to peening jets. The invention comprisesessentially the use of a distribution tank from which slurry underpressure is supplied to a plurality of outlets feeding the peening jets.The supply outlets are all arranged so that each jet is supplied withthe slurry at substantially like pressure.

This invention relates to components for use with peening apparatus. Itis particularly directed to the distribution system for peening suppliesto be fed to peening nozzles for application to work under treatment.

Normally, in peening apparatus, work to be treated is either subjectedto the action of dry peening components, such as hardened steel, cobaltor other similar metal balls forced against the work through a nozzleunder the influence of some type of fluid pressure system, such as anair jet. In other forms of peening apparatus, it has been found thatpreferred results are achieved where the work to be treated is subjectedto the action of a slurry formed of a liquid and a pre-establishedconcentration of some type of peening component. In most instances, thepeening component that is included in the liquid slurry and which issuflicient to make the slurry of the selected concentration is a glassbead or ball of extremely small size.

For many types of work, the glass bead or ball is to be preferredbecause it is both hard and yet resilient and can be formed in extremelysmall size with great uniformity. Glass balls used for such types ofpeening ap paratus may be made which vary only within extremely minorlimitations from a size as small as 0.001 inch in diameter up to, say0.004 inch in diameter. These glass balls are often fed along with wateras the sustaining liquid to be directed outwardly from a peening jetunder the influence of some suitable type of fluid, such as air, forcedinto the nozzle area at relatively high pressure.

The peening solution or slurry is also supplied at some selectedpressure above atmospheric through a distributor element, then to be fedinto the nozzles into which the high pressure air is also directed. Thisserves to both draw the slurry from the distribution tank by suction andalso to force the slurry at high pressure against the work to betreated.

In many instances in the past it has been customary to provide theslurry and to feed it into a manifold from which different outlets wereprogressively provided to direct the material to the differentsuccession of nozzles. In the average form of manifold, the first outletusually was so located that substantially the pressure of the slurryfeeding pump is maintained. The slurry then feeds along with theinjected air or other fluid through the nozzle against the work. As aslurry from the source of supply is forced through the distributor andmanifold, an inherent drop in pressure occurs because of the distancefrom the source and then also at each outlet in the sequence from thedistribution point down to that outlet in the manifold which is mostremote from that end at which the slurry enters. The result has beengenerally that the 3,490,489 Patented Jan. 20, 1970 ice slurry at thedistant outlets is released under less pressure than at the head end,due primarily to the greater distance of flow from the distributionpoint of the manifold, and consequently the slurry from the last outletwill not be as dense as at that outlet nearest the source ofdistribution and the slurry concentration is reduced.

Remote nozzles then actually receive less solids in the slurry than doothers and consequently a lack of uniform peening of the work towardwhich the nozzles are directed frequently occurs. This is particularlyof substantial significance where the work is held stationary for alimited period of time and is then stepped along to bring a complete newsection into the outlet region of the different nozzles.

Where the work is moving continously with respect to a whole series ofnozzles, this is generally not quite as significant as for intermittentmotion but, nonetheless, if the nozzles are so arranged as to betransverse to the work some portions of the work within the region ofthe nozzle outlets tend to be peened to a greater extent than some othersections of the work. As a result of this, the hardness of the workacted upon may differ to some extent. If this occurs, the efficiency ofoperation of the system as a whole decreases rapidly.

In the instance of turbine blades, where some nozzles direct theiroutput closer to the root of the blade and others direct their outputnearer to the edge of the blade, a marked difference in the bladetreatment can occur because of such difference in the slurryconcentration.

This invention has as its aims and objects those of providing for theobtainment of substantially uniform concentration of the impactingslurry at all regions so that the slurry fed into any nozzle is ofapproximately the same concentration. Then, when the nozzles direct theoutput of the slurry along with the feeding air supply, the treatmentwhich each section of the work within the range of the supply nozzlesreceives is approximately the same.

This objective is achieved according to the present invention byproviding a tank or distribution element into which the slurry input isfed from a suitable pump at a suitable pressure and from which tank theoutput of the slurry is taken at points where the slurry concentra tionand pressure is substantially equal. Usually the distribution tank isformed more or less as a cup-shaped element with the inlet from thesupply pump feeding in at the bottom. Numerous outlet connections fromsubstantially along a circumferential path are arranged about thedistribution tank and are generally equally angularly spaced. Theconnections of the peening nozzles to the distribution tank are thenprovided by short length conduits, usually flexible in nature, leadingto one entrance port of a projecting nozzle. The input slurry normallyfeeds into the nozzle chamber. All slurry feeding into the nozzlechamber is then ejected under the force of some form of fluid, such asair, which is fed into the same nozzle chamber and is of sufficientforce to draw the slurry along with it as it is forced toward the nozzleoutlet.

In a refined form of the invention, the distribution tank is so providedthat as the input slurry from the source feeds into the tank, suflicientpressure is created internally of the tank to close an air valve so thatall slurry within the tank is fed out at each of the exit ports insubstantially equal volume. The air closure element is so arranged thatit is adapted to open as soon as the pressure within the slurry feedingpassage from its pump is reduced below an optimum pressure value atwhich the slurry is most easily fed into the various outlet connectionsand at which pressure the air valve closes. The opening of the air valveis sufficient to break any vacuum condition which might exist in thedistribution tank and thus promptly permit any slurry contained withinthe distribution tank as well as the slurry line promptly to drain backthrough the pump and into a suitable source of supply.

Various modifications of the arrangement may be provided as desired butthe invention in one of its preferred forms has been illustrated by theaccompanying drawings wherein FIG. 1 illustrates in diagrammatic formthe general plan of operation of the assembly showing the pump, thedistribution tank and the slurry nozzles directed toward the :work;

FIG. 2 shows in vertical section the upper part of the slurrydistribution tank taken along the line 2-2 of FIG. 1 and FIG. 3 shows atop view of the distribution tank as the slurry is fed from it.

If reference is now made to the drawings, the slurry distribution tank11 is provided with an inlet passage 12 at its lower end from which, byway of a suitable connection 13, slurry of any desired concentration maybe fed from the pump, schematically shown at 14. The connection pointsare shown at 15 from which the slurry can be released to the nozzleelements.

The nozzle elements 20 and 21, of which there may be any desired number,are shown as directing their output (shown in dotted outline) toward anassumed work-piece which can be regarded for illustrative purposes asthe edge of a turbine blade. In the form in which the distribution tankis shown, there is a series of outlet connections 25, 26, 27 and 28which lead outwardly from the distribution tank 11 to flexibleconnecting members, such as those diagrammed at 30 and 31, which connectinto the nozzle chambers illustrated schematically at 32 and 33. Fluidunder pressure (such as air) is also supplied into the nozzle chambers.The fluid is derived in most instances from some separate source (notshown), such as a tank, and is fed in by way of the inlet ports 35 and36 so that any slurry fed into the nozzle chambers 32, 33 will be forcedoutwardly toward the work element.

With the slurry feeding into the distribution tank 11 by way of theconnecting tube 13 from the pump 14, it is apparent that in the plane ofthe outlet connections 25 through 28 the pressure will be approximatelythe same. Therefore, the pressure at which the slurry is feeding throughthe tubes illustrated at 30 and 31, for instance, into the chambers ofthe ejecting jets 21 and 20, respectively, will be approximately thesame (assuming the same size and length feed tube). The slurry, infeeding into the distribution chamber 11, is fed in at suflicientpressure to close the check valve 40 and make the edges 41 of the checkvalve seat tightly against the inner upper portion 42 of thedistribution tank and thereby close the tank 011 against the inlet ofair through the opening 43 formed adjacent to the bracket 44 whichsuspends the edges of the check valve internally of the distributiontank.

Under these circumstances whenever the slurry is being fed through thetube 13 to the distribution tank 11, the check valve closes and thepressure build up within the tank 11 forces the slurry outwardly throughthe connections 25 through 28. However, at times when the pump 14 ceasesto force slurry through the tube 13 to the tank 11, the weight of thecheck valve 40 is sufficient to permit it to drop down and to permit therectangular support element 44 to rest against the top surface 45 of thedistribution tank 11. This permits motion of the check valve 40 up anddown as indicated by the arrows adjacent to it and immediately lets airinto the tank 11 to break any vacuum which might be created.

oftentimes, it has been found that the slurry may tend to cling to thesurface of the check valve and particularly to the protruding edges 40thereof. Consequently, to avoid this possibility, it is occasionallydesirable to be able manually to turn the check valve to a limitedextent and to move it up and down manually at times when the pump 14 iscut off. This is done by the pin element 46 which extends outwardly fromthe bolt 47 which threads through the rectangular support element 44thereby to hold the entire assembly in place. The bolt may be knurled atits outer end to make turning the same by hand relatively easy.

Various other modifications may, of course, be made in the structuredescribed without departing in any respect from the essence of theinvention or the features of novelty hereinabove described.

Having now described the invention, what is claimed is:

1. A distribution system for feeding slurry to peening nozzlescomprising:

a substantially circular cross-section slurry distribution tank,

means to supply the tank with slurry adapted to be directed thereto froma pressure source to build up within the tank pressure approximatingthat of the source,

a plurality of generally uniformly spaced outlet taps from the tank atspaced regions whereat each outlet pressure is substantially initiallyequal,

an air vent check valve in the upper section of the tank in a regionabove that of any of the outlet taps, said air inlet being adapted to beclosed when the pressure of the supplied slurry exceeds a selectedoptimum value, and

means to cause the air vent to open at time periods when the supplypressure drops below the selected optimum.

2. A distribution system as in claim 1 comprising, in addition, means toraise and lower the check valve manually thereby to release to the tankany slurry which might collect at times of supply cut-cit.

References Cited UNITED STATES PATENTS 2,219,259 10/1940 Horn 137-2173,204,942 9/1965 Matthys et al 137561 HENRY S. J AUDON, Primary ExaminerUS. Cl. X.R. 29--90; 137-583

